By Tim Craig, Washington Post BAGRAM AIR BASE, Afghanistan — The U.S. Army’s 10th Mountain Division formally concluded its operations in Afghanistan on Tuesday, another sign that the war is drawing to a close even as American commanders are evaluating whether they will have enough resources to support the fledgling Afghan military. After five tours in Afghanistan since 2001, four of which included operations in the country’s volatile and dangerous eastern provinces, most of the soldiers from the division will be en route to Fort Drum in New York by Wednesday afternoon. A few dozen soldiers will stay behind for another week or two, but division commanders said their work in Afghanistan was…